1. Field of the Invention.
This invention relates to germicidal compositions, and more particularly relates to an improved dry germicidal sponge.
2. Background.
Iodine is a well-known germicide with activity against a wide range of bacteria and viruses, and much effort has been directed to finding satisfactory vehicles for its administration. Carriers of iodine, often termed iodophors, are generally polymeric materials which form complexes with iodine. Polyurethanes are disclosed as iodophors by Shelanski in U.S. Pat. No. 3,235,446 and by LaVeen in U.S. Pat. No. 4,381,380.
Polyvinylpyrrolidone (povidone, PVP) is a well known iodophore which forms a stable complex with iodine (hereinafter P-I). This complex has been extensively used in germicidal preparations such as aerosols, ointments and cleansing compositions for topical application. The structure of P-I is discussed by Schenck et al. in the Journal of Pharmaceutical Sciences 68, 1505 (1979).
Lorenz et al. in U.S. Pat. No. 4,769,013 discloses an interpenetrating polymer network (IPN) foam complex of PVP and polyurethane which absorbs iodine from an aqueous solution and then releases the iodine slowly when the dry sponge is contacted with water.
Although not concerned with iodine delivery, Creasy, in U.S. Pat. No. 4,642,267 and Winn, in U.S. Pat. No. 4,373,009 disclose complexes of polyurethane and PVP. In the Creasy et al. patent, a blend of PVP and polyurethane is applied to a substrate surface as a hydrophilic coating. In the Winn et al. patent, a copolymer of povidone with a hydroxyethyl acrylate is applied as a lubricious coating to a substrate surface by first priming the surface with an isocyanate and then reacting the isocyanate with the copolymer.
Iodophor-iodine complexes have been impregnated into a sponge or brush used for germicidal cleaning or scrubbing. Often, such implements are included in a kit of materials which may also include other items useful for patient preparation, such as towels, gloves and the like. Prior art iodophors and iodine complexes made therefrom suffer from various deficiencies such as instability leading to loss of iodine titer and tissue sensitivity due to the corrosive effects of iodine. On the other hand, the complex of polyurethane and P-I of U.S. Pat. No. 4,769,013, because of the IPN nature of the patented product, delivers iodine too slowly to be useful in a sponge for surgical scrubbing.
While the above disclosures have improved the delivery of iodine, further improvements, particularly an iodine carrier complex providing substantially instantaneous delivery of iodine is needed. The present disclosure is directed to fulfillment of this need.